Photogrammetry vs. Laser Scanning

Updated: Jan 23, 2019


Hand measuring for as-builts is taxing. It takes tons of time, resources, and you end up with inaccurate data. Photogrammetry and laser scanning are both cost effective alternatives that save time and offer highly accurate information that can be turned into to point clouds and BIM models. However, you’ll want to educate yourself on the capabilities and limitations of each before scanning a project. For our purposes we will be focused on scanning vertical construction and not civil or surveying in this blog post.





Photogrammetry

Photogrammetry can be done with almost any instrument that takes photos – yes, that even means your cellphone or GoPro. Using multiple photographs and Autodesk Recap you can create measurements and generate 3D models of objects. However, the reliability of those measurements is going to directly correlate with the tool you’re using. Standard practice in the AEC industry for photogrammetry of interiors has lead to using a Matterport scanner.

Matterport captures both depth and color quickly and is backed by powerful cloud processing. This tool has been highly popular in the real-estate industry because it creates beautiful deliverable 360 tours, it has been catching on in the AEC industry as well. Matterport scans can be converted in to point cloud files (basically x,y,z coordinates forming objects), that be easily imported into Autodesk ReCap Pro and turned into Building Information Models (BIM).


Matterport

Pros

  • Quick – individual scans take about 30 seconds.

  • Creates beautiful deliverable 360 tours.

  • Easily use for marketing

  • Create interactive walk throughs for your website that can be displayed easily using HTML.

  • Attractive high-quality images.

  • Can be turned into point clouds & BIM Models (OBJ file).

  • Great for facilities management.

  • Generally accurate data, within 1% of reality.

  • Completely automated, doesn’t require manual alignment.

Cons

  • Matterport cannot scan exteriors (do to lighting 2D panoramic images can be taken).

  • Not as accurate as LiDAR scans.

  • Light is an issue -building must be well lit.

  • Matterport models up to 200 scans – covering 10,000 square feet. Larger commercial buildings can take up multiple models to view a building regionally.


Laser Scanning

What is Laser Scanning? Think RADAR but with light. Laser scanning is also known as LiDAR (LIDAR or LADAR). The accuracy of LiDAR scanning is unprecedented, with accuracy within millimeters at a distance of ten meters. The output of a LiDAR scan is a point cloud, a set of data points that represents x, y, z coordinates in space. These scans can be used in Autodesk Recap ®, Autodesk Revit ®, Autodesk Infraworks ® and more.

There are a variety of ways to collect laser scans, from units on tripods, drone, to handheld. For interior buildings the most accurate scans are from units on tripods.


Pros

  • Highly accurate -The BLK360 performs within six millimeters at ten meters.

  • Exteriors of buildings can be scanned because the sun/light does not affect scanning.

  • Quick scans.

Cons

  • Not all LiDar has photo tied to it, meaning no color. Make sure you find a scanner that fits your needs.

  • The imagery generally isn't used as easily for marketing purposes, but it can be done.


Both types of scanning provide great outcomes, there are just slight differences that you may want to consider for the outcome. Pairing with a provider like On Point Scans can help you decide which type of scanning best fits your needs.


Other things to keep in mind when looking into both LiDAR and Photogrammetry:

  • No item works properly in bad weather

  • Both can be done by drone, units on tripods, or handheld devices.





By Cassandra Vagher


Call us for a consultation today! 720-646-2624 or email us at cassandra@onpointscans.com

On Point Scans uses both LiDAR and Photogrammetry technology to capture as-builts. We create 3D Photo Models and well as Building Information Models (BIM) for your team to use. Learn more here.







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